Search Publications

Unveiling the Distant Universe: Characterizing z ≥ 9 Galaxies in the First Epoch of COSMOS-Web
DOI: 10.3847/1538-4357/ad5e6a Bibcode: 2024ApJ...973...23F

Finkelstein, Steven L.; Bagley, Micaela B.; Casey, Caitlin M. +48 more

We report the identification of 15 galaxy candidates at z ≥ 9 using the initial COSMOS-Web JWST observations over 77 arcmin2 through four Near Infrared Camera filters (F115W, F150W, F277W, and F444W) with an overlap with the Mid-Infrared Imager (F770W) of 8.7 arcmin2. We fit the sample using several publicly available spectra…

2024 The Astrophysical Journal
Gaia eHST JWST 40
EMPRESS. XIII. Chemical Enrichment of Young Galaxies Near and Far at z ∼ 0 and 4–10: Fe/O, Ar/O, S/O, and N/O Measurements with a Comparison of Chemical Evolution Models
DOI: 10.3847/1538-4357/ad13ff Bibcode: 2024ApJ...962...50W

Ono, Yoshiaki; Ouchi, Masami; Harikane, Yuichi +14 more

We present gas-phase elemental abundance ratios of thirteen local extremely metal-poor galaxies (EMPGs), including our new Keck/LRIS spectroscopy determinations together with 33 James Webb Space Telescope z ∼ 4–10 star-forming galaxies in the literature, and compare chemical evolution models. We develop chemical evolution models with the yields of…

2024 The Astrophysical Journal
JWST 40
Building the First Galaxies—Chapter 2. Starbursts Dominate the Star Formation Histories of 6 < z < 12 Galaxies
DOI: 10.3847/1538-4357/ad1923 Bibcode: 2024ApJ...964..150D

Carniani, Stefano; Bunker, Andrew J.; Stark, Daniel P. +12 more

We use SEDz*—a code designed to chart the star formation histories (SFHs) of 6 < z < 12 galaxies—to analyze the spectral energy distributions (SEDs) of 894 galaxies with deep JWST/NIRCam imaging by JADES in the GOODS-S field. We show how SEDz* matches observed SEDs using stellar-population templates, graphing the contribution of each epoch b…

2024 The Astrophysical Journal
JWST 40
A Strong He II λ1640 Emitter with an Extremely Blue UV Spectral Slope at z = 8.16: Presence of Population III Stars?
DOI: 10.3847/2041-8213/ad4ced Bibcode: 2024ApJ...967L..42W

Arrabal Haro, Pablo; Ji, Zhiyuan; Brammer, Gabriel +12 more

Cosmic hydrogen reionization and cosmic production of the first metals are major phase transitions of the Universe occurring during the first billion years after the Big Bang; however, these are still underexplored observationally. Using the JWST/NIRSpec prism spectroscopy, we report the discovery of a sub-L * galaxy at z spec

2024 The Astrophysical Journal
eHST JWST 40
The SN 2023ixf Progenitor in M101. II. Properties
DOI: 10.3847/1538-4357/ad414b Bibcode: 2024ApJ...968...27V

Van Dyk, Schuyler D.; Matheson, Thomas; Howell, Steve B. +12 more

We follow our first paper with an analysis of the ensemble of the extensive preexplosion ground- and space-based infrared observations of the red supergiant (RSG) progenitor candidate for the nearby core-collapse supernova SN 2023ixf in Messier 101, together with optical data prior to the explosion obtained with the Hubble Space Telescope (HST). W…

2024 The Astrophysical Journal
AKARI Herschel eHST 40
Lensed Type Ia Supernova "Encore" at z = 2: The First Instance of Two Multiply Imaged Supernovae in the Same Host Galaxy
DOI: 10.3847/2041-8213/ad4648 Bibcode: 2024ApJ...967L..37P

Pérez-Fournon, I.; Fox, O. D.; Diego, J. M. +60 more

A bright (m F150W,AB = 24 mag), z = 1.95 supernova (SN) candidate was discovered in JWST/NIRCam imaging acquired on 2023 November 17. The SN is quintuply imaged as a result of strong gravitational lensing by a foreground galaxy cluster, detected in three locations, and remarkably is the second lensed SN found in the same host galaxy. Th…

2024 The Astrophysical Journal
eHST JWST 39
UNCOVER: JWST Spectroscopy of Three Cold Brown Dwarfs at Kiloparsec-scale Distances
DOI: 10.3847/1538-4357/ad206f Bibcode: 2024ApJ...962..177B

Nanayakkara, Themiya; van Dokkum, Pieter; Fujimoto, Seiji +19 more

We report JWST/NIRSpec spectra of three distant T-type brown dwarfs identified in the Ultradeep NIRSpec and NIRCam ObserVations before the Epoch of Reionization (UNCOVER) survey of the Abell 2744 lensing field. One source was previously reported as a candidate T dwarf on the basis of NIRCam photometry, while two sources were initially identified a…

2024 The Astrophysical Journal
eHST JWST 39
JWST and ALMA Multiple-line Study in and around a Galaxy at z = 8.496: Optical to Far-Infrared Line Ratios and the Onset of an Outflow Promoting Ionizing Photon Escape
DOI: 10.3847/1538-4357/ad235c Bibcode: 2024ApJ...964..146F

Ouchi, Masami; Koekemoer, Anton M.; Richard, Johan +33 more

We present Atacama Large Millimeter/submillimeter Array (ALMA) deep spectroscopy for a lensed galaxy at z spec = 8.496 with $\mathrm{log}({M}_{\mathrm{star}}/{M}_{\odot })\sim 7.8$ whose optical nebular lines and stellar continuum are detected by JWST/NIRSpec and NIRCam Early Release Observations in the field of SMACS J0723.3–7327. Our …

2024 The Astrophysical Journal
Gaia eHST JWST 39
Stellar Half-mass Radii of 0.5 z < 2.3 Galaxies: Comparison with JWST/NIRCam Half-light Radii
DOI: 10.3847/1538-4357/ad02ee Bibcode: 2024ApJ...960...53V

Bell, Eric F.; Franx, Marijn; Muzzin, Adam +13 more

We use CEERS JWST/NIRCam imaging to measure rest-frame near-IR light profiles of 435 M > 1010 M galaxies in the redshift range of 0.5 < z < 2.3. We compare the resulting rest-frame 1.5-2 µm half-light radii (R NIR) with stellar half-mass radii ( ${R}_{{{M}}_{\star }}$ ) derived with mu…

2024 The Astrophysical Journal
eHST JWST 39
Brown Dwarf Candidates in the JADES and CEERS Extragalactic Surveys
DOI: 10.3847/1538-4357/ad20d1 Bibcode: 2024ApJ...964...66H

Johnson, Benjamin D.; Lyu, Jianwei; Eisenstein, Daniel J. +13 more

By combining the James Webb Space Telescope (JWST)/NIRCam JADES and CEERS extragalactic data sets, we have uncovered a sample of 21 T and Y brown dwarf candidates at best-fit distances between 0.1 and 4.2 kpc. These sources were selected by targeting the blue 1–2.5 µm colors and red 3–4.5 µm colors that arise from molecular absorption …

2024 The Astrophysical Journal
eHST JWST 38